Polymethin dyes and intermediates



Patented Oct. 11, 1949 POLYMETHIN DYES AND IN TERMEDIATES Frances M.Hamer, Russell J. Rathbone, and Barbara Seaton Winton, Harrow,Wealdstone, England, assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Application February 1,1947, Serial No. 725,960. In Great Britain February 22, 1946 Thisinvention relates to polymethin dyes and i intermediates, and to aprocess for preparing the same.

In a copending application of Edward B. Knott, Serial No. 604,521, filedJuly 11, 1945, it is shown that cyclarnmonium quaternary saltscontaining a ll-anilinovinyl group in the ozor 'y-position can beprepared by condensing a cyclammonium quaternary salt containing areactive methyl group wherein R1 and Ari have the values given above,

12 Claims. (Cl. 260240) R2 represents a member selected from the groupconsisting of an alkyl group, an aralkyl group and an aryl group, e. g.methyl, ethyl, n-propyl, n-butyl, isobutyl, benzyl, phenyl, etc., 11represents a positive integer of from 1 to 2, and Z represents thenon-metallic atoms necessary to complete a heterocyclic nucleuscontaining from to 6 atoms in the heterocyclic ring, e. g. adihydropyridine, a dihydroquinoline, a thiazoline, a thithe3-alkyl-2-methylene-6:7-benzin the oror -position, with a compoundselected azolidine, a benzthiazoline, a naphthiazoline, a from thoserepresented by the'following general selenazoline, a benzselenazoline,an indoline nu- 1 f ul cleus, etc.

A N=CH 0R, Typical heterocyclic nitrogen bases having a wherein Arirepresents an aryl group of the ben- 11 55 3 P f f 2g g 553 2 g zeneseries, e. g. phenyl or substituted phenyl and Y :2 19 4 e R1 representsan aliphatic group, e. g. alkyl, sub- 1; T5 i g stituted alkyl or anunsaturated aliphatic group. we A i i 3 met-Y1 methylene'' Typicalcompounds represented by the above ii it i $f general formula are thealkylisoformanilides, 00 y ene i mes 1 1 e. g. methylisoformanilide,ethylisoformanilide, eneben.ZthwiZ 0T0-3"ebhy. 2 methy1gne npropylisoformanilide, n butylisoformanilide, btinzthlazohneg'n'butyl'z'methylenebenztiuaz' isobutynsoformamude, etc -o l1ne,5-chloro-3-ethyl-2 methylenebenzthiazo- We have now found that acompound of the i t ethyl'5'methoxy"2'methylenebenztmaz' above generalformula will condense with a heter- Q5 ii f 12? a g fi fig f m ocyclicnitrogen base having a methylene group mes me Anew blaze attached to thecarbon atom in the aor 'y-posig a 3 th 1 2 th 1 tion to the ternarynitrogen atom to give a heter- 2 g i 5 y g i g ocyclic nitrogen basehaving a dianiloisopropylienz enz lazolme g he dene group in the dor'y-position to the ternary methyleneAz5'benzbenzthlazoltnes i nitrogenatom. From these new dianiloisoproi ie l' pylidene intermediatespolymethin dyes can be fl i- *2- formed. alkyl-2-methylene-A -selenazol1nes (e. g. 3,4-d1- It is, accordingly, an object of ourinvention meihyl-z-methylene A 3'methy1' to provide new dyeintermediates. A further ob- 2-methY1ene-4"Phem1'ehselenmlm, etc) theject is to provide a process for preparing 81161135 3-alkyl-2-methylenebenzselenazolmes (e. g. 3- intermediates. A stillfurther object is to proethyl-2-methylenebenzslenazolme, 3 methyl-2 videa process for preparing dyes from such intermethylenebegzseienazohne ai' mediates. Other objects will become apparent meihylenfcqumomleshereinafterene-1,2-d1hydroqumo11ne, 1 ethyl-2-methy1ene- The reaction bywhich our new dia'niloisopro- 40 llz'dlhydroflumolmeg etcy) the1a1ky14'methy1' pylidene intermediates are formed can be repene 1Adlhydlfoqumomfles resented as follows: methylene-1,4 d1hydroqu1no11ne,l-ethyll-methylene-1,4-dihydroquinoline, etc), the 1,3,3-tripr -nalkyl-2-methyleneindolines (e. g. 1,3,3-trimethyl-, R-N (oH=0H)..-1 G=0i RlOCH=NAr1 I Z-me'thyleneindoIine, 1 ethyl 3,3 dimethyl-Z- CH=NAnmethyleneindoline, etc.) etc. We have further found that a compound ofthe R N (OHCH)-CG zRoH above general formula Ar1N=CH-OR1 will alsoCH=NATI condense-with a heterocyclic nitrogen base hav- Iing ananiloethylidene group in the uor 'y-posiwherein R1, Ar1, R2, n and Zhave thdvaluesgiven above and Arz represents aryl group of the benzeneseries, e. g. phenyl, p-methoxyphenylg-p ethoxyphenyl, p-tolyl,p-chlorophenyl, etc.

Typical heterocyclic nitrogen bases having an aniloethylidene group inthe mor -position are: the 3-alkyl-2-aniloethylidene-A -thiazolines (e.g. 3,4-dimethyl-2-aniloethylidene-A -thiazoline,-3-ethyl-4-phenyl-2-aniloethylidene-M-thiazoline, etc.) the3-alkyl-2-aniloethylidenebenzthiazolines (e. g.3-methy1-2-aniloethylidenebenzthiazoline, 3 ethyl 2aniloethylidenebenzthiazoline, etc.), the3-alkyl-Z-aniloethylidenefiz'i-benzbenzthiazolines (e. g. 3-methyl-2-aniloethylidene-6 7 -benzbenzthiazoline, l ethyl --2aniloethylidene 6:7 benzbenzthiazoline, etc.), the1-alky1-2-aniloethylidene-4 -benzbenzthiazolines (e; g.1-methyl2-aniloethylidene4':5- benzbenzthiazoline, 1 -ethyl 2--aniloethylidene- 4:5-benzbenzthiazoline, etc.), the- 3'-alkyl-2-aniloethylidene-A -selenazolines (e. g. 3,4-dimethyl 2 aniloethylidene Aselenazol-ine, 3- methyl 4-phenyl-2-aniloethylidene-n -selenazo line,etc.), the 3-alkyl-2-aniloethylidenethiazolidines (e. g.3-methy1-2-aniloethylidenethiazolidine, 3 ethyl 2 aniloethylidenethiazolidine, etc.) the 3-alkyl-2-aniloethylidenebenzselenazolines (e. g. 3-methyl-2-aniloethylidenebenzselenazoline,3-ethyl-2-p-chloroaniloethylidenebenzselenazoline, etc.) the 1-alkyl2-aniloethylidene- 1,2-dihydroquinolines (e. g.1-methyl-2-ani1oethylidene-1,2-dihydroquinoline,I-ethyl-Z-aniloethylidene-1,2-dihydroquinoline, etc.),- the 1- alkyl -4-aniloethy1idene 1,4 dihydroquinol ines (e. g.1-methyl-4-ani1oethylidene-1,4-dihydroquinoline,1-n-buty1-4-aniloethylidene-L i-dihydroquinoline, etc.), the3-alkyl-2-aniloethy1- idenebenzoxazoline (e. g. 3-methyl-2-aniloethyhidenebenzoxazole, 3 ethyl 2 aniloethylidenebenzoxazolines, etc.) etc.

Either of the above condensations is advantageously carried out byheating, employing a water-binding agent, such as zinc chloride as acondensing agent. The dianiloisopropylidene compound is then obtained asa zinc chloride complex from which the dianiloisopropylidene compoundcan be isolated by treatment with an alkali, e. g. an alkalimetal-hydroxide (-for instance sodium hydroxide, potassium hydroxide) oran alkali metal alcoholate, e.- g. sodium ethylate.

We have found that the dianiloisopropylidene intermediate can becondensed with a cyclammonium quaternary salt (quarternary salt of aheterocyclic nitrogen base) having a methyl group in the ocor'y-POSitiOII to the quaternary nitrogen atom to give polymethine dyes.In this condensation one molecular proportion of thedianiloisopropylidene compound reacts with two molecular proportions ofthe quaternary salt to give polymethine dyes which can be represented bythe following general formula:

wherein R2, n and Z have the values given above, R3 represents an alkyl,aralkyl or aryl group, e. g. those set forth under R2 above, Xrepresents an anion, e. g. chloride, bromide, iodide,benzenesulfo'nat'e', p-toluenesulfonate, perchlorate, methylsulfate,ethylsulfate, acetate, thiocyanate, etc., Z1 represents the non-metallicatoms necessary to complete a heterocyclic nucleus selected fromheterocyclic nuclei containing from 5 to 6 atoms in the heterocyclicring, e. g. the heterocyclic nuclei set forth under Z above.

Typical cyclammonium quaternary saltshaving a reactive methyl group inthe aor -position are: the 2-methylthiazole alkyl quaternary salts (e.g. 2-methy1thiaz0le ethiodide, 2-methyl-4- phenylthiazolemetho-p-toluenesulfonate, 2,4- dimethylthiazole ethiodide, etc.), the2-methy1- benzthiazole alkyl quaternary salts (e. g.2'-methylbenzthiazol'e ethiodide, 4-chloro-2-methylbenzthiazolen-propobromide, 5-chloro-2-m'ethylbenzthiazole etho-p-toluenesulfonate,2-methyl- 4 phenylbenzthiazole ethiodide, 2 methyl- 5 phenylbenzthiazoleethiodide, 2-methylbenzthiazolefi-carboxyethobromide, etc.) theZ-methyl- 6:7-benzbenzthiazole alkylquaternary salts (e. g. 2-methyl-6'I-benzbenzthiazole etho-p-toluenesulfonate,2-methyl-6:7-benzbenzthiazole ethiodide, etc.), the2-methyl-4:5-benzbenzthiazole alkyl quaternary salts (e. g.2-methyl-4:5-benzbenzthiazole ethiodide, 2-methyl-4z5 benzbenzthiazoleetho-p-toluenesulfonate, etc.), the 2- methyloxazole alkyl quaternarysalts (e. g. 2&- dimethyloxazole ethiodide, 2methyl-4-phenyloxazoleethiodide, etc.), the 2-alkylbenzoxazole alkyl quaternary salts (e. g.2-methylbenzoxazole ethiodide, 2-methyl-5-phenylbenzoxazolen-butobromide, 5-chloro-2-methy1benzoxazole ethiodide, etc.), the2-methy1-6:7-benzbenzoxazo1e alkyl quaternary salts (e.- g;Z-methyl-Gz'l-benzbenzoxazole methiodide, 2-'methyl-6:7-benzbenz oxazoleethiodide, etc.), the 2-methyl-4rz5-benzbenzoxazole alkyl quaternarysalts (e. g. 2- rne'thyl-4:5-benzbenzoxazo1e ethiodide,Z-methyl-4z5-benzbenzoxazole n-propi'odide; etc.), theZ-methylselenazole alkyl quaternary salts (e; g. 2;4-di'methy1selenazoleethiodide, 2-methyl-4 phenylselenazole ethiodide, etc.), the2-methylbenz'sele'nazole alkylquaternary salts (e. g.Z-methylbenzselenazole ethiodide, 2-methylbenzselenazoleetho-e'thylsulfate, 5-chloro-2-methylbenzs'elen'azole methop-toluenesulfonate, etc.), the Z-methylthiazoline alkyl quaternary salts(e. g. 2-methylthiazoline methiodide, Z-methylthiazoline ethiodide,etc.), the quinaldine alkyl quaternary salts (e. g. quinaldineethiodide, quinaldine carboxymethobromide, quinaldine ,6-h'ydroxyethiodide, quinaldine B-ethoxyethiodide, etc.), the lepidinealkyl quaternary salts (e. g. lepidine n-butiodide, lepidine ethiodide,lepidine carboxymethiodid'e, etc.), the 1,3',3-trimethylcr am biUUillndolenine alkyl quaternary salts (e. g. 1,3,3- trimethylindoleninealkyl quaternary salts (e. g. 1,3,3-trimethylindolenine methiodide,1,3,3-trimethylindolenine ethiodide, etc.), the 2-methylbenzimidazolealkyl quaternary salts (e. g. 1,2-dimethyl-3,4-trimethylenebenzimidazole methylsulfate,1,2-dimethylbenzimidazole metho-methylsulfate, etc), etc.

The above dyes of formula II can exist in more than one resonanceconfiguration and either one of the anions (X) may be shown associatedwith the nitrogen atom carrying the R2 group.

Certain of the dyes of the above general formula I wherein Z and Z1 allrepresent the same heterocyclic nucleus have been prepared before, V12.

1. Those in which all three nuclei are 4-quinoline nuclei by Clarke inUnited States Patent 1,804,674, dated May 12, 1931, and by Hamer, J.Chem. Soc. 1927, 2796 and 1928, 1472.

2. Those in which all three nuclei are thiazole nuclei by Brooker inUnited States Patent 1,994,- 562, dated March 19, 1935.

3. Those in which all three nuclei are benzthiazole, a-quinoline,u-pyridine or benzimldazole nuclei by Ogata, Bull. Inst. Phys. Chem.Res. Tokyo 13, 491 to 500 (1934).

Although the structure of the dyes given by Brooker in United StatesPatent 1,994,562 diflers from that given herein, the synthetic method ofthe present invention, wherein a A -thiazoline having a methylene groupor an aniloethylidene group in the 2-position is condensed with athiazole quaternary salt having a methyl group in the 2-position, givesa neothiazolocarbocyanine dye having the same properties as the oneobtained by Brooker from the same Z-methylthiazole quaternary salt. Themethod of the present invention, therefore, establishes the chemicalstructure of neothiazolocarbocyanines as that put forward by Konig,without published supporting evidence in Z. Wiss. Phot. 39, (1935).

The method described by Ogata is related in some respects to thatalready used by Hamer, supra, and by Brooker. We have not been able toisolate the u-quinoline or a-pyridine dyes by Ogatas method, but the dyewhich we have prepared by his method from Z-methylbenzthiazole ethiodidehas been proved to be identical with the dye prepared by the presentinvention from 3 ethyl 2 dianiloisopropylidenebenzthiazoline andZ-methylbenzthiazole ethiodide.

The present invention, however, enables us to obtain dyes not hithertoknown, in which the three nuclei are the same but do not consist ofthiazole, benzthiazole, a-quinoline, v-quinoline or benzimidazolenuclei. The invention, therefore, includes such new dyes as are depictedby formula II above wherein Z and Z1 represent nuclei selected from thegroup consisting of pyridine, naphthoquinoline, benzbenzthiazoles,selenazole, benzselenazole, benzoxazole and indolenine nuclei.

The condensations to form the dyes of formula I are advantageouslycarried out in the presence of a basic condensing agent, for instanceatertiary amine (pyridine, triethylamine, tri-npropylamine,tri-n-butylamine, N-methylpiperidine, N -ethylpiperidine,dimethylaniline, diethylaniline, etc.) or an alkali metal carboxylate(sodium acetate, potassium acetate, etc.) in the presence of a carboxylicanhydride (acetic anhydride, propionic anhydride, etc.). Heataccelerates the condensations.

The present invention also enables us to obtain dyes not hitherto knownin which the three nuclei are not the same, i. e. those represented byformula II wherein Z and Z1 each represents the non-metallic atomsnecessary to complete a different heterocyclic nucleus, the differencebeing in the nuclear atoms themselves or in nuclear substituent groupsor in both, or in the position of linking which may be alpha or gamma.In these new dyes two of the nuclei (Z1) are alike but difier from theother (Z).

We have further found that one molecular proportion of a heterocyclicternary nitrogen base having a dianiloisopropylidene group in the 02- or'y-position to the ternary nitrogen atom (formula I) can be condensedwith substantially one molecular proportion of a cyclammonium quaternarysalt (quaternary salt of a heterocyclic nitrogen base) having a methylgroup in the 11- or 'y-position to the quaternary nitrogen atom to givea polymethine dye which can be represented by the following generalformula:

III R wherein R2, 11, Z, An, Z1, R3 and X have the values given above.

The condensations to form the dyes of formula III above areadvantageously carried out in the presence of a basic condensing agent,e. g. the basic condensing agents recited above. Heat accelerates thecondensations.

Although the condensations (formula III) just described above take placebetween one molecular proportion of the dianiloisopropylidene compoundand one molecular proportion of the cyclammonium quaternary saltcontaining the reactive methyl group, it is not essential to employthose molecular ratios durin the condensation. It is, however, generallynecessary to conduct the condensation at a lower temperature or heat fora shorter time than when preparing the dyes of formula II.

We have found that the dyes of formula III above can be condensed withcyclammonium quaternary salts having a methyl group in the 11- or'yposition to the quaternary nitrogen atom (e. g. the cyclammoniumquaternary salts set forth above) to give polymethine dyes which can berepresented by the following general formula:

wherein R2, 11, Z, R3, X and Z1 have the values given above, and Z2represents the non-metallic atoms necessary to complete a heterocyclicnucleus containing from 5 to 6 atoms in the heterocyclic ring, e. g. theheterocyclic nuclei set forth under Z above. If Z, Z1 and Z2 eachrepresents the non-metallic atoms necessary to complete the sameheterocyclic nucleus or if Z1 and Z2 each represents the non-metallicatoms necessary to complete the same heterocyclic nucleus which isdiiferent from the heterocyclic nucleus of which Z represents thenon-metallic atom necessary to complete, the dyes obtained by thiscondensation can also be obtained by the con- 76 densation describedunder formula II above.

Where 2, Z1 and Z2 each represents the non-metallic atoms necessary tocomplete a different heterocyclic nucleus, the dyes are not obtainableby any other known process.

These condensations of the dyes of formula III with a cyclammoniumquaternary salt are advantageou'sly effected in the presence of a basiccondensing agent, e. g. th basic condensing agents set forth above.

We have further found that one molecular proportion of a heterocyclicnitrogen base having a dianiloisopropylidene group in the uor'y-position to the ternary nitrogen atom (formula I) can be condensedwith substantially two molecular proportions of a compound having areactive methylene group adjacent to an electro-negative group, such asa carbonyl or thiocarbonyl group, to give a novel kind of polymethinedye of the following general formula:

wherein R2, n and Z have the values given above, X1 represents a memberselected from the group consisting of an oxygen and a sulfur atom, and Qrepresents the non-metallic atoms necessary to complete a cyclic nucleuscontaining from 5 to 6 atoms in the ring, especially a cyclic nucleuswherein the atom attached to the carbon atom of the group is an atomselected from the group consisting of an oxygen atom, a sulfur atom anda nitrogen atom. Typical examples of cyclic nuclei containing from 5 to6 atoms in the ring are:

cyclic nuclei of the hydantoin series, of the 2- thiohydantoin series,of the oxydihydroquinoxaline series, of the 2-thio-2,4(3,5)-oxazoledioneseries, of the 5-0xazolone series, of the benzo- B-morpholone series, ofthe indoxyl series, of the rhodanine (2-thio-2,4(3,5) -thiazoledione)series, of the 4-thiazolidone series, of the pseudothiohydantoin series,of the 2,4(3,5)-thiazoledione (2,4-dihydroxythiazole) series, of theketodihydrobenzparathiazine series, of the 2-amino-4(5) thiazoloneseries, of the 2-mercapto-4(5) -thiazolone series, of the barbituricacid series, of the 2- thiobarbituric acid series, of the1,3-diketo-hydrindene (indandione) series, of the 5-pyrazolone series,of the 5-thiopyrazolone series, of the isothiohydantoin series, of the2,4 diketo,-1,2,3,4- tetrahydroqulnoline (2,4-dihydroxyquinoline)series, tetronic acid, of the coumaranone series, of the oxindoleseries, of the dihydrocarbostyril series, homophthalimide succimide,etc.

The cyclic compounds containing a reactive methylene group adjacent to acarbonyl or a thiocarbonyl group can be represented by the followinggeneral formula:

VI Q

VII rm wherein D represents a member selected from the group consistingof an oxygen atom, a sulfur atom and a group wherein R4 represents amember selected from the group consisting of alkyl (including aralkyland other substituted alkyl) and aryl groups, and Q1 represents thenon-metallic atoms necessary to complete a cyclic nucleus containingfrom 5 to 6 atoms in the ring. Typical examples Of the compoundsrepresented by general formula VII are: 3-alkyl 2 thio-2,4(3,5)-oxazolediones (e. g. 3-rnethyl-, 3-ethyl-, 3-n-propyl-, 3-nbuty1-,3-lauryl, etc.) 3-sulfoalkyl-2-thio-2,4(3,- 5)-oxazolediones (e. g.3-sulfomethyl-, etc.), 3- carboxyalkyl-2-thio-2,4(3,5) -oxazolediones(e. g. 3-carboXymethyl-), 3-alkyl-rhodanines (e. g. 3- methyl-,3-ethyl-, 3-n-propyI-, 3-n-butyl-, 3- lauryl, etc.), 3-arylrhodanines(e. g. 3-pheny1-, B-B-naphthyb, B-p-dimethylaminophenyl-, etc.), 3carboxyalkylrhodanines (e. g. 3 carboxymethyl-, 3-a-carboXyethyl-, 3-3-carboxyethyl-, 3-(1,3-dicarboxy-n-propyl) etc.),3-sulfoalkylrhodanines (e. g. 3-sulfomethyl-, 3-B-sulfoethy1-, etc.)3-carboxyarylrhodanines (e. g. B-p-carboxyphenyl-,3-(3-carboxy-4-hydroxy) phenyl-, etc.) 3-sulfophenylrhodanines (e. g.3-p-sulfophenyl-, 3-(2,5-disulfophenyl) etc.), 4-thiazolidone, 2-amino-4(5) -thiazolones (e. g. 2-methylphenylamino-,2-ethylphenylamino-, 2-diphenylamino-, etc.), thioxindoxyl,ketodihydrobenzparathiazlne, 2-thiohydantoin,l-alkyl-3-aryl-2-thiohydantoins (e. g. 1-methyl-3-phenyl-,1-ethyl-3-phenyl-, etc.), 1,3-diaryl-2-thiohydantoins (e. g.1,3-diphenyl-, etc.) etc.

The condensations to give the dyes of formula V are advantageouslyeffected by heating in the presence of a basic condensing agent, e. g.a. tertiary amine (for instance pyridine, triethylamine,tri-n-propylamine, tri-n-butylamine, triisoamylamine,N-methylpiperidine, N-ethylpiperidine, etc.). An alkali metalcarboxylate, e. g. sodium or potassium acetate, in the presence ofacetic anhydride, can also be used as basic condensing agent.

We have also found that one molecular proportion of a heterocyclicternary nitrogen base having a dianiloisopropylidene group in the aor'y-DOSitiOIl to the ternary nitrogen atom (formula I) can be condensedwith substantially one molecular proportion of a compound having areactive methylene group adjacent to an electro-negative group, such asa carbonyl or thiocarbonyl group, to give a novel kind of polymethinedye which can be represented by the following general formula:

VIII

wherein R2, 11, Z, An, Q and X1 have the values given above.

The condensations to form the dyes of formula VIII above areadvantageously carried out in the presence of a basic condensing agent,e. g. the basic condensing agents set forth above. Heat accelerates the-condensations.

Although the condensations (formula VIII) just described above takeplace between one molecular proportion of the dianiloisopropylidenecompound and one molecular proportion of the compound having thecarbonyl or thiocarbonyl group, it is not essential to employ thesemolecular ratios during the condensation. It is, however, generallynecessary to conduct the condensations at lower temperatures or heat fora OEHKUH HUU 9 shorter period of time than when preparing the dyes offormula V.

We have found that the dyes of formula VIII above can be condensed withcompounds containing an electronegative group (e. g. the compounds setforth by formulas VI and VII) to give polymethine dyes which can berepresented by the following general formula:

I/QR OH=(-C=Xz wherein R2, n, Z, Q and X1 have the values set forthabove, and Q2 represents the non-metallic atoms necessary to complete acyclic nucleus containing from 5 to 6 atoms in the ring (e. g. those setforth under formula V) and X2 represents a member selected from thegroup consisting of an oxygen and a sulfur atom. If Q1 and Q2 and X1 andX2 represent the same species, the dyes obtained by this condensationcan also be obtained by the condensation described under formula Vabove. If Q1 and Q2 represent different species or if X1 and X2represent different species, the dyes are not obtainable by any otherknown process.

These condensations of the dyes of formula VIII with a compoundcontaining a carbonyl or thiocarbonyl group are advantageously effectedin the presence of a basic condensing agent, e. g. the basic condensingagents set forth above.

We have also found that the dyes of formula VIII can be condensed withcyclammonium quaternary salts having a methyl group in the aorv-position to the quaternary nitrogen atom (e. g. the cyclammoniumquaternary salts set forth above) to give novel polymethine dyes whichcan be represented by the following general formula:

wherein R2, n, Z, Q,-X1, Z1, R3 and K have the values given above. Thesame dyes can be prepared, we have found, by condensing the dyes offormula III with a compound containing a carbonyl or thiocarbonyl group(e. g. those described under formulas VI and VII.) Either of thesecondensations just described are advantageously carried out in thepresence of a basic condensing agent, e. g. those described above.

The following examples will serve to illustrate further the manner ofpracticing our invention.

Example 1.3-ethyl-2-dianiloisopropylidenebenzothiazoline c=o lHl3-ethyl-2-methy1enebenzothiazole (3 g.; 1 mol.), ethylisoformanilide (25cc.; 10 mols.) and zinc chloride (6 g.; 2.6 mols.) were heated at175-180 C. for 3 hours. While still warm, the reaction mixture wastreated with acetone (30 cc.). The solid was filtered oil. when cold,washed with acetone, then with water, then again with acetone, and wasfinally boiled .out with methyl alcohol in which the sand-colored zinccomplex of the dianilo compound is scarcely soluble. To convert thecomplex into the base, it was stirred mechanically with acetone (300cc.) and 30% (by weight) aqueous sodium hydroxide cc.) after cooling,the acetone layer was separated. filtered and dried over solid sodiumhydroxide, and then concentrated. The above-formulated dianilo base wasfiltered off when cold and recrystallized from methyl alcohol. It wasobtained as yellow crystals, M. P. 126 C., which gave a deep yellowspirit solution.

Example 2.3-ethyl-Z-dianiloisopropylidenebenzothiazoline The dianilobase of Example 1 was prepared by heating together3-ethyl-2-aniloethylidene benzothiazoline (1 mol.) which has thefollowing formula:

with ethylisoformanilide (10 mols.)v and zinc chloride (2.6 mols.), andisolating the dianilo base from the zinc chloride complex as in Example1.

E'mample 3.5-chloro-3-ethyl-2-dlaniloisopropylidenebenzthiazoline5-chloro-3-ethyl 2 methylenebenzthiazoline (24 g.) zinc chloride powder(47 g.) and ethylisoformanilide (1'70 g.) were heated together in an oilbath at C., with mechanical stirring, for 1 hours. The reaction mixturewas treated with acetone and the solid filtered off, washed with water,and boiled out with methyl alcohol. The resultant zinc chloride complexwas ground with 40% sodium hydroxide solution (400 cc.) and water (200cc.) and extracted with acetone (5000 cc.). The extract was dried withstick sodium hydroxide, the solvent distilled off under a vacuum, andthe concentrate cooled, when the base crystallized. It could berecrystallized from methyl alcohol. The yellow crystals had M. P.187-188 C. with previous shrinking. Abs. max. 4100 A. in methyl alcohol.The base sensitized a gelatino-silver-chloride photographic emulsion upto 4700 A.

Example 4.3-ethyl-Z-dianiloisopropylidene-G:7- benzbenzthiazoline laHl3-ethyl-2-methylene 6.:7 benzbenzthiazoline, zinc chloride, andethylisoformanilide were caused to react as in Example 3 and the zincchloride complex was similarly isolated and converted into base. Afterrecrystallization from methyl alcohol, the dull yellow crystals meltedat about 173 0. Abs. max. 3890 A. in methyl alcohol.

Example 5. 3 ethyl 2 dianiloisopropylide'nebenzselenazoline Example 6.-3ethyl 2 dianiloisopropylidenebenzselenazoline This compound (alsodescribed in Example 5) was prepared by heatingB-ethyl-Z-aniloethylidenebenzselenazoline 20 g.) ethylisoformanilide (44g.) and zinc chloride (18 g.) at ISO-170 C. for 30 minutes. The productwas treated with water and the solid then ground and washed with acetoneand boiled out with methyl alcohol (1400 cc.). The residual zincchloride complex was converted to base by treatment with aqueous sodiumhydroxide solution and acetone. The filtered acetone extract was driedover stick sodium hydroxide and then concentrated, when the basecrystallized.

Example 7 .-4-methyl-3-ethyl 2 dz'aniloisopropylidene-M-thiazoline CzHt4-methyl-3-ethyl-2 aniloethylidene A thi azoline (48.8 g.),ethylisoformanilide (152 g.) and zinc chloride (80 g.) were heatedtogether at ISO-170 C. for 2 hours with mechanical stirring. The crudezinc chloride complex was washed with acetone, and then with water, andwas boiled out with methyl alcohol (3200 cc.). The residual zincchloride complex was converted to base by shaking with aqueous sodiumhydroxide solution and acetone. The acetone extract was concentrated tosmall bulk and the base thrown out by addition of ice water. The goldenyellow crystals had M. P. 111 C. (decomp.). Abs. max. 3475 A. in methylalcoholic solution.

Example 8.3-methyl-Z-dianiloisopropylidenethiazolidine 3-methyl -2-aniloethylidenethiazolidine (10.2 g.), ethylisoformanilide (70 c.) andzinc chloride (19.13 g.) were heated together at 175-180 C. for 1%;hours. The viscous mass was treated with acetone (150 cc.). Theresultant solid was well washed with water and boiled out four timeswith methyl alcohol (125 cc. 4.). To liberate the free base from thezinc chloride complex, this complex (8 g.) was ground with acetone (120cc.) and the mixture cooled with ice and stirred mechanically. Anice-cold solution of sodium (2 g.) in absolute alcohol (120 cc.). andstirring with cooling, were applied for 10 minutes. The solid wasfiltered off and washed with acetone 16 cc.). The filtrate and washingswere poured into ice-cold water. which precipitated the base. It wasfiltered off and could be recrystallized from light petroleum. B. P. 100C. The lemon yellow crystals had M. P. 127 C. Abs. max. in methylalcoholic solution 3720 A.

Example 9.--3-ethyl-Z-dianiloiopropylidenethiazolidine The zinc chloridecomplex was prepared as in Example 8 from3-ethyl-2-aniloethylidenethiazolidine, ethylisoformanilide, and zincchloride, and was similarly converted into the free base. Afterrecrystallization from light petroleum, B. P. 80-100" 0., the brightyellow crystals had M. P. 104 C.

Example 1 0.-1 -ethyl- 4-dianilois0propylidene- 1 :4 -dihydroquinolineCalls-N A mixture of 1-ethyl-4-methylene-1:4-dihydroquinoline (10.44g.), ethylisoformanilide (90.5 cc.). and zinc chloride (25 g.) wereheated together at 1'75-185 C., with mechanical stirring, for 1% hours.The reaction mixture was repeatedly warmed with acetone (total 450 cc.)until all lumps had been disintegrated. After filtering ed the solid andwashing with acetone, it was ground with water and finally boiled outthrice with methyl alcohol (400 cc. 3). The bright orange residue ofzinc chloride complex was converted into free base by the method used inExamples 8 and 9. The base was precipitated by water from itsalcohol/acetone suspension as a yellow solid, which had become brownbefore it could be filtered oif. After washing with water it was driedin a vacuum desiccator. This crude base was used in subsequent dyecondensations. It could however be recrystallized from light petroleum,B. P. 40-60 C. When heated, the light brown powder began to shrink atC.; decomposition was gradual and the substance was quite black by 154C. but without any definite M. P.

The methyl alcoholic solution had absorption maxima at 4785 and 4020 A.

Example 11 .1 -ethyl-2-dianiloisopropylidene- 1 :Z-dihydroquinoline1-ethyl-2-methylene-1 :Z-dihydroquinoline was heated as in Example 10with ethylisoformanilide and zinc chloride; after treatment of the zincchloride complex with acetone, water, and hot methyl alcohol, it wasconverted into base by the same method as in Examples 8, 9 and 10. Thebase was a dirty yellow when first precipitated but darkened. It waspossible to recrystallize it from light petroleum, B. P. 80-100 C. Thelight brown powder had no definite M. P.; shrinking began at about C.and considerable decomposition had occurred by C. The broad absorptioncurve of a methyl alcoholic solution had its maximum at 4100 A.

2,484,508 13 14 Example 1z 3- gmz the dark bronze solid had M. P. 216 C.(decomp.). benzorazoline Abs. max. at 6350 A. with an inflexion to the3-ethyl -2- aniloethylidenebenzoxazoline (106 g.), ethylisoformanilide(300 cc.), and zinc chloride (168 g.) -Were heated together at l50l60 C.for 1 hour. The reaction mixture was heated with acetone and the solidboiled out with methyl alcohol (1600 cc.). The resultant zinc chloridecomplex was warmed and shaken with 20% sodium hydroxide solution (7.5cc. per g.) and acetone (65 cc. per g.). After concentration, theacetone extract was precipitated with aqueous ammonium chloridesolution. The base was purified by suspending in spirit (20 cc. per g.)and acidifying with concentrated hydrochloric acid (4 cc. per g.). Thefiltered solution was treated with ammonia and the precipitated basefiltered off and washed. It could be recrystallized from methyl alcohol.The bright yellow crystals had M. P. 210 C. (decomp). The absorptionmaximum of a methyl alcoholic solution was at 3755 A.

Example 13.-[Bis-2- (3-ethylbenzothiazole) l [on- ,8'-climethin-2(3-ethylbenzthiazole) ltrimethincyamne diiodide .ether, andrecrystallized from methyl alcohol,

from which it came down as brassy crystals, giving a blue spiritsolution. Unlike the better known types of cyanines, this dye is fairlyreadily soluble in water.

Example 14.[Bis-2-(3-ethyZ-6:7-benzbenzthiazole) [a5-dimethin-2'(3-ethyl-6': 7-ben2- benzthiazole) ltrimethin-cyanine diiodide This wasprepared as in Example 13, from 3- ethyl-2-dianiloisopropylidene-6 :7-benzbenzthiazoline, 2-methyl 6:7 benzbenzthiazole ethiodide, andpyridine. After recrystallization from spirit curve at 5900 A. The dyedid not sensitize and depressed blue sensitivity.

Example 15.[Bis2-(5-chZ0ro-3-ethylbenzthiazole) [afl'-di17lthi7Z-2' (5'chlor0-3' ethylbenzthz'azole) ltrimethincyanine diiodide 5chloro-3-ethyl-2-dianiloisopropylidenebenzthiazoline (1.56 g.),5-chloro-2methylbenzthiazole ethiodide (2.55 g.), anhydrous sodiumacetate (1.23 g.), and acetic anhydride (10 cc.) were boiled together inan oilbath at C. for 10 minutes. The cooled mixture was filtered and thesolid washed with ether and with water.

After recrystallization from methyl alcohol the green crystals had M. P.240 C. (decomp.) Abs.

max. at 6105 A. The dye strongly depressed the blue sensitivity of aphotographic emulsion.

Example Iii-[Bis 2 3-(ethylbenzselenazole) l- [(15 dimethin-Z'(3'-ethylbenzselenazole)ltrimethincyanine diiodide Prepared by method ofExample 13, but from 3- ethyl 2-dianiloisopropylidenebenzselenazoline,2-methylbenzselenazole ethiodide, and pyridine, and recrystallized frommethyl alcohol. The dull green crystals had M. P. 226 C. (decomp.). Abs.max. at 6200 A. Strong photographic desensitization.

Example 17.-[Bis-2-(4 methyl 3 ethylthiazole)1[B'-dimethin-2'-(sf-methyl3 ethylthz'azole) ltrimethincyanine diiodide Example 18.- [Bis-2(3-methyl-A -thiazoline) [afi'-dimethin 2'-(3'- methyl-A -thiazoline)trimethincyam'ne dz'iodz'de Prepared by heating together3-methyl-2-dianiloisoprqpylidenethiazolidine, 2 methyl A thiazolinemethiodide, and pyridine as in Example 13. After recrystallization frommethyl alcohol, it was obtained as purplish red crystals. When heated,they began to shrink at about 115 C. and had largely melted anddecomposed by 125 C. but there was no definite M. P. Abs. max. at 5065A. The dye sensitized a gelatino-silverbromide emulsion up to 5900 A.

Example 19.[Bis 2 (3 ethyl-A -thiazoline) [:x,8'-dimthi7l 2' (3 ethyl-A-thiazoZineH trimethincyanine diperchlorate This was prepared as inExample 18 but from 3-ethyl-2 dianiloisopropylidenethiazolidine andZ-methyl-fl-thiazoline ethiodide in pyridine. The dye iodide wasprecipitated by absolute ether and subsequently treated with a solutionof sodium perchlorate, to convert it into the corresponding perchlorate.After recrystallization from methyl alcohol the brick red crystals hadM. P. 230 C.. (decomp). Abs. max. at 5060 A. It sensitized agelatino-silver-bromide emulsion up to 5700 A.

Example 20.[Bis-4-(I-eth-ylquinoline) [aB'-dimethin 4-(1-ethylquinoline)trimetlhincyanz'ne diiodide This was prepared by heating together crudel-ethyl 4 dianiloisopropylidene 1:4 dihydroquinoline, lepidineethiodide, anhydrous sodium acetate, and acetic anhydride. Afterwashing, the dye was recrystallized from methyl alcohol. It proved to beidentical with a sample of neocyanine iodide which had been obtainedempirically (Hamer, J. Chem. 800., 1928, 1472).

Example 21.[Bis-2- (l-ethylquinoline) l [aB'-dimethin2-(1-ethylquin0line) trimethincyanine diperchlorate Crude1-ethyl-2-dianiloisopropylidene-1:2-dihydroquinoline, quinaldineethiodide, sodium acetate, and acetic anhydride were heated together.The dye iodide was precipitated with absolute ether and washed withether and with water. It was taken up in hot methyl alcohol andconverted into the perchlorate by treatment with aqueous sodiumperchlorate solution. On recrystallization from methyl alcohol, it was avery dark green solid. Abs. max. 6795 A. in methyl alcohol.

Examples 22.-Bis [2-(1 -ethylquinoline) T-dimethz'n2'-(1-ethylquin0line)] trimethincyanine diiodide CzHs I A mixture ofcrude l-ethyl-4-dianiloisopropylidene-l:4-dihydroquinoline (0.75 g.),quinaldine ethiodide (1.20 g.), anhydrous sodium acetate (1.31 g.), andacetic anhydride (8 cc.) was heated at 135-140 C. for 10 minutes. Thesolid was filtered oil and Washed successively with acetic anhydride,ether, water, and methyl alcohol, and

' per g.).

was recrystallized from methyl alcohol cc.

The greenish gold crystals gave 011 solvent from about C., began toshrink at about C. and had M. P. 264 C. (decomp). Abs. max. at 6725 A.in methyl alcohol. The dye showed photographic desensitizing but nosensitizing.

Example 23.-l4-(1-euhylquinoline) l [2-(3-ethyln -thiazolz'ne)[ap'-dimethin 2 (3 -ethyl-A thz'azoline) l trimethincyaninediperchlorate This was prepared as in Example 22, but with 2-methyl-A-thiazoline ethiodide instead of quinaldine ethiodide. The dye wasprecipitated from the reaction mixture with absolute ether and waswashed with water. Its solution in methyl alcohol was treated hot withaqueous solution of sodium perchlorate. The dye perchlorate was tiwcerecrystallized from methyl alcohol. The dark blue crystals melted atabout 260 C. (decgmp). Abs. max. of methyl alcoholic solution at 5270 A.

Example 24.--[4-(l-ethylqninoline) [2- (3-benz thiazole) [ap-dimethin 4(1 ethylquinoline) trimethincyanine dziodide Example 25.[2-(1-ethylquinoline) [2- (ti-ethy benzthzazole) l-[y/Y-dimethin 2' (1ethylquinoline)l trimethincyanine diz'odide This was prepared by heatingtogether 3-ethyl- 2-dianiloisopropylidenebenzthiazoline, quinaldineethiodide, and pyridine. The dye was precipitated with absolute etherand heated with methyl alcohol as in Example 24. It was recrystallizedfrom methyl alcohol and obtained as green crystals. M. P. about 249 C.(decomp), abs. max. in methyl alcoholic solution 6365 A. The dyesensitized a gelatino-silver-bromide emulsion from 6600-6900 A.

Example 26. [2 (3 ethylbenzoxaeole) l [2-(3- ethylbenzthiaeole) ['yfldimethin 2 (3- ethylbeneoxazole) l-trimethincyanz'ne diiodide This wasprepared as in Example 25 but with 2-methylbenzoxazole ethiodide insteadof quinaldine ethiodide. Th precipitate obtained with ether was heatedwith methyl alcohol, and the solid was twice recrystallized from methylalcohol. The bronze crystals had M. P. 236 C. (decomp.). Abs. max. of amethyl alcoholic solution 5400 A. It sensitized from 5600-6000 A. anddepressed the normal blue sensitivity.

Example 27. [2- (3-ethylbenzthz'azole) ][2-(3- ethylbenzselenazole)[afi' dimethin 2- (3'- ethylbenzselenazole) ltrimethincyanine diiodide 3ethyl-2-dianiloisopropylidenebenzthiazoline (0.19 g.; 1 mol.)2-methylbenzselenazole ethiodide (0.35 g.; 2 mols.) and pyridine (2 cc.)were heated together at 135140 C. for 5 minutes. The dye was filteredofi, washed and recrystallized from methyl alcohol, from which itseparated as green ULHHUH 17 Crystals, giving a blue spirit solution.The dark green crystals had M. P. about 235 C. (decomp.), with previoussoftening, but dependent upon rate of heating. In methyl alcoholicsolution the absorption maximum was at 6155 A. with a secondary maximumat 5580 A. The dye showed no sensitizing, but only desensitizing actionon a photographic silver halide emulsion.

Example 28.-[2- (I-ethylquinoline) [2-(3-ethylbenzselenazole) [vcdimethin 2- (1'- ethylquinolzne) Jtrimethincyanine diiodide3-ethyl-2-dianiloisopropylidenebenzselenazoline (1.72 g.), quinaldineetho-p-toluenesulfonate (3.42 g.), anhydrous sodium acetate (1.32 g.)

and acetic anhydride (30 cc.) were heated together at 145-l50 C. for 5minutes. The hot reaction mixture was treated with an aqueous solutionof potassium iodide. The crude dye iodide was purified by boiling outwith methyl alcohol and the residue was recrystallized from methylalcohol. The green and gold crystals had M. P.

235 C. (decomp.) Abs. max. 6435 A. for a methyl alcoholic solution. Thedye desensitized a photographic silver halide emulsion.

Example 29. [2 (3 ethylbenzoxazole) [2-( ethylbenzselenazolefl ['yfi'dimethin 2 (3'- ethylbenzoxazole) ltrimethincyanine diiodide Prepared byheating together 3-ethyl-2-diani- 1oisopropylidenebenzselenazoline, 2methylbenzoxazole ethiodide and pyridine, precipitated by absoluteether, and washed with water. By fractional recrystallization frommethyl alcohol it was freed from a less soluble impurity. The dark redcrystals had M. P. 215 C. (decomp.). Abs. max. at 5965 A. for a methylalcoholic solution. It sensitized a gelatino-silver-bromide emulsionfrom 540045100 A. with the maximum at 5850 A. and

depressed the blue sensitivity.

Example 30.[2-(3-ethylbenzthiazole)l [2 (3 ethylbenzselenazole) [75dimethin 2' (3' ethylbenathiazole) ltrimethincyanine diiodide Preparedas in Example 29 but with Z-methylbenzthiazole ethiodide instead of2-methylbenzoxazole ethiodide. Precipitated, washed, and recrystallizedas in Example 29. The dark green crystals had M. P. 235 C. (decomp.).Abs. max. at 6085 A. for a methyl alcoholic solution. It

caused some depression of blue sensitivity of a gelatino-silver-halideemulsion.

Example 31 .--[2- 3-ethyl-6 :7 -benzbenzthiazole) l [2-(3-ethylbenzselenazole) ['yc-dimethin 2'- (3'-ethyl 6' :7benzbenzthiazole) ltrzmethincyanine diiodide This was prepared byheating together 3-ethyl- 2 dianiloisopropylidenebenzselenazoline, 2

methyl-6 :7 -benzbenzthiazole ethoptoluenesulfonate, and pyridine, andtreating the hot reaction mixture with an aqueous solution of potassiumiodide. By fractional crystallization from methyl alcohol a more solubleimpurity was removed.

The bronze crystals had M. P. 193 C. (decomp.).

A. max. 6405 A. for a methyl alcoholic solution.

The dye depressed the blue sensitivity of a photographic silver halideemulsion.

Example 32.--[2- (1 :3:S-trimethylindolenine) [2- (3ethylbenzselenazole) 5' dimethin 2' (1 ':3:3'trimethylindolenine)ltrimethincyanine diperchlorate 3-ethyl 2dianiloisopropylidenebenzselenazoline, 2:3:3-trimethylindoleninemethiodide, an-

hydrous sodium acetate, and acetic anhydride 18 were heated together andthe reaction mixture was treated with a hot solution of sodiumperchlorate. Fractional recrystallization from methyl alcohol removed amore soluble impurity. 5 The dark bluish green crystals had M. P. 252 C.

(decomp.). Abs. max. at 6115 A. with a secondary maximum at 5720 A. fora methyl alcoholic solution. The dye considerably depressed bluesensitivity of a silver halide emulsion.

10 Example 33.[2-(4-methyl-.l-ethylthiaeole)1E2- B-ethylbenemiazole) 1[ada'imethin 2' k3- ethylbenzthiazole) ltrz'methincyanine diiodide4-methyl-3-ethyl-2-dianiloisopropylidene A thiazoline,Z-methylbenzthiazole ethiodide, and pyridine wer heated together. Dyecrystallized and was recrystallized from methyl alcohol. The green andgold crystals had M. P. 247 C. (decomp.) Abs. max. at 6075 A. for methylalcoholic solution. The dye sensitized from 5700-6900 A., with themaximum at 6500 A. and depressed blue sensitivity of a photographicsilver halide emulsion.

Example 34.[3-(4-methyl-3-ethylthiazole) 1E2- (B-ethylbenzselenazole)[aB-dimethin-2'- (3- ethylbenzselenaaole) ltrz'methincyanine diiodide Itwas prepared by heating together 3-ethyl-2-dianiloisopropylidenethiazolidine (1.12 g.), 2- methylbenzthiazoleethiodide, and pyridine, and crystallized on cooling. The washed productwas boiled out with, and recrystallized from, methyl alcohol (10 cc.,1070 cc.). The green and gold crystals had M. P. 237 C. (decomp.). Abs.max. at 6070 A. for a methyl alcoholic solution.

Example 36.---[4-(l-ethylqumoline) [2-(3-ethyln -thiazoline)l-[yB'dimethin-4' (1 ethylquinoline)] trimethincyanz'ne diiodide Thiswas prepared by heating together 3-ethyl-2-dianiloisopropylidenethiazolidine, lepidine ethiodide, anhydroussodium acetate, and acetic anhydride at 130-140" C. for 2 minutes. Thecrystalline dye was filtered off, washed, and boiled out with, andrecrystallized from, methyl alcohol. The golden crystals melted at 272C. (decomp.). Abs. max. at 7440 A. in methyl alcoholic solution.

Example 37.-[S-(B-ethylrhodanine) l [2-(3-ethylbenzthiazole)[,B-methin-5 (3-ethylrhodanine) dimethznmerocyam'ne 3-ethyl2-dianiloisopropylidenebenzthiazollne (0.77 g.; 1 mol.),3-ethylrhodanine (0.97 g.; 3 mols.), anhydrous sodium acetate (0.98 g.;12 mols.) and acetic anhydride cc.) were heated together at'140-150" C.for 10 minutes. The cooled reaction mixture was treated with absoluteether (40 00.). The crude dye was filtered off, washed with ether,ground with water and recrystallized from pyridine. The green and goldcrystals had M. P. 229 C. with previous shrinking. A methyl alcoholicsolution showed a broad absorption band with maxima at 5090 A., 5225,5350 and 5600. The dye desensitized a photographic silver halideemulsion.

Example 38.-[5- (3-ethylrhodanine) [2- (3-ethylbenzselenazole)lfi-mzthin-F-(B ethylrhodanine) ldimethinmerocyam'ne 3 ethyl 2dianiloisopropylidenebenzthiazoline line (1.08 g.; 1 mol.),3-ethylrhodanine (1.21 g.; 3 mols.), and anhydrous sodium acetate (0.82g.; 4 mols.) in acetic anhydride cc.) were heated together at 145 C. for7 minutes. Solid was precipitated from the chilled reaction mixture byaddition of ether, and was filtered off. The crude dye was washed withwater, dried, and recrystallized from a mixture of equal volumes ofpyridine and ethyl alcohol. The dark green solid had a gold reflex andM. P. 206 C. (decomp.). Abs. max. at 5300 A. in methyl alcohol solution.The dye imparted a trace of photographic sensitization to a silverhalide emulsion with maximum at about 5850 A. and depressed the normalsensitivity of the emulsion.

Example 39.[5-(4-lceto-2-thio 3-ethyltet1'ahydro orrazole) [2(3-ethylbenzselenazole)llfimethin5'-(4'-keto-2'-thio-3'-ethyltetrahydroorazole)ldimethinmerocyanine Prepared as in Example 38, but replacing the 3-ethylrhodanine with an equivalent amount of 4-keto-2-thio-3-ethyltetrahydro-oxazole. The dye was recrystallized from amixture of pyridine and ethyl alcohol (1:1). The scarlet crystals had M.P. 231 C. (decomp.). Their methyl alcoholic solution had a broadabsorption curve with its principal maximum at 5000, one slightly weakerat 5100, and a shoulder at 5300 A. In a gelatinosilver-bromide emulsion,the dye reduced the normal sensitivity, but caused extra sensitivity to6200 A. with the maximum at 5550 A.

Example 40.--[2-(4-methyl-3-ethylthiazole) l [5- (3-ethylrhodanine)[a-methin-5' (3 ethylrhodamneH dimethinmerocyanine Prepared fromii-methyl-3-ethyl-2-dianiloisopropylidene-A -thiazoline,3-ethylrhodanine, and pyridine. The crude dye was precipitated withwater and was caused to solidify by treatment with spirit.Recrystallization from pyridine gave greyish blue crystals of M. P. 223C. (decomp.). The narrow absorption curve of a methyl alcoholic solutionhad its maximum at 5720 A. and an infiexion at 5220. The substanceconsiderably reduced the blue sensitivity of a photographic silverhalide emulsion and weakly sensitized to 6600 A. with the maximum at6450. Instead of pyridine as condensing agent in the preparation,anhydrous sodium acetate in acetic anhydride could be used.

Example 41 5- (4- keto-2-thio-3-ethyltetrahydro-oxazole) [2-(4-methyl3-ethylthiazole) [e-methin-5'-(4'-lceto-2-thio 3'ethyltetrahydro-oxazoleH dimethinmerocyanine4-methyl-3-ethyl-2-dianiloisopropylidene A thiazoline (1.39 g.),4-keto-2-thio-3-ethyltetrahydro-oxazole (1.74 g.) anhydrous sodiumacetate (1.31 g.) and acetic anhydride (20 cc.) were heated together atl45-150 C. for 7 minutes. The mixture was poured into water. Theresultant tarry solid was caused to solidify by treatment with spirit.After recrystallization from methyl alcohol the compound consisted ofdark purple crystals, M. P. 189 C. (decomp.). The narrow absorptioncurve of a methyl alcoholic solution had its maximum at 5350 A. and aninflexion at 5000. It sensitized a gelatino-silver-brornide emulsionvery weakly to 5700 A., the maximum being at 5400, and it considerablydepressed the normal sensitivity of the emulsion.

Example 42. [5- 3 ethylrhodam'ne) l [2 (5- chloro 3 ethylbenzthiazole)[,8 methin 5'- (3 '-ethylrhod.anine) ldimethinmerocyanine 5 chloro 3ethyl 2 dianiloisopropylidenebenzthiazoline (2.60 g.), 3-ethylrhodam'ne(3.15 g.), and pyridine (25 cc.) were heated together at 30-135 C. for 5minutes. The dye was precipitated with water, and filtered off; more wasextracted from the filtrate with ether and precipitated from theconcentrated extract with water. After recrystallization from pyridinethe bronze powder had M. P. 128- 30 C. (decomp.), with previousshrinking. The methyl alcoholic solution had a broad absorption curvewith maximum at 5080 A The dye weakly sensitized agelatino-silver-bromide emulsion from 5500- 5900 A, with strongdepression of the blue sensitivity.

Example 43.[5-(1 phenyl 3 ethyl 2 thiohydantoin) [2 (5 chloro 3 ethzlbenzthiazole) 1E6 methin-S' (1 phenyl 3' ethyl- 2'-thiohydantoin)]dimethinmerocyanine 5 chloro 3 ethyl 2dianiloisopropylilidenebenzthiazoline (3.12 g.), l-phenyl-S-ethyl-2-thiohydantoin (4.96 g.) anhydrous sodium acetate (3.72 g.), and aceticanhydride (20 cc.) were heated together at Mil- C. for 10 minutes. Thereaction mixture was treated with absolute ether and the sodium acetatewas filtered off. The ether was distilled ofi from the filtrate and theresidue treated with water. The resultant product by twocrystallizations from methyl alcohol was obtained as dark greencristals, M. P. 174 C. (decomp.). Abs. max. 5180 in methyl alcohol. Thedye decreased the normal sensitivity of a geiatino-silver-bromideemulsion but sensigized up to 6700 with the maximum at 6150 Example44.[5 (2 diphenylamino 4 keto- A thiazoline) [2 (5 chloro 3ethylbenzthiazcle) [B-methin-S'-(2'-diphenylamino-4- keto-n -thiazoline)ldimethinmerocyanine This was similarly prepared except that thephenyl-3-ethyl-2-thiohydantoin of Example 43 was replaced by2-diphenylamino-4-keto-A -thiazoline. The cooled reaction mixture wastreated with absolute ether and the resultant solid was ground withwater. After recrystallization from pyridine it was obtained as aterracotta powder, M. P. 193-194 C. (decomp.). Abs. max. 4955 A. The dyeproduced no sensitization of a silver halide emulsion but slightdepression of blue sensitivity.

Example 45.[-(4-Iceto-2-thio-3-ethyltetrahydro-orazole) l [2-(3-methyl-A-thiazoline) 11pmethin-5-(4-keto-2'-thio-3-ethyltetrahydroozrazole)ldimethinmerocyanine S-methyl 2 dianiloisopropylidenethiazolidine (1.61g.), 4-keto-2-thio-3-ethyltetrahydro-oxazole (1.60 g.), anhydrous sodiumacetate (2.46 g.), and acetic anhydride (8 cc.) were heated together at130-140 C. for 5 minutes. The solids were filtered off when cold, Washedwith ether, and ground with water, and the resultant dye wasrecrystallized from pyridine. It was a reddish orange solid, M. P. about229 C. with previous darkening and shrinking. There were two absorptionmaxima of a methyl alcoholic solution, the stronger one lying at 4455 A.and another at 5030.

Example 46.-[4- (I-ethylquinoline) l [2- (3-ethylbenzthiazole) lanilomethyltrimethincyanine iodide CgHs 3 ethyl 2dianiloisopropylidenebenzthiazoline (3.07 g.) and lepidine ethiodide(2.40 g.) were mixed, treated with pyridine (16 cc.) and heated forminutes at 60-70 C. The dye was precipitated with ether, well washedwith water, and washed with ether in a Soxhlet apparatus. Byrecrystallization from methyl alcohol it was obtained as a dark greenpowder, M. P. 218-219 C. (decomp.). The blue methyl alcoholic solutionbecame flame colored on acidification. Abs. max. of an ammoniacal methylalcoholic solution was at 6030 A, whilst one containing sulfuric acidhad abs. max. at 5000 A. It was a photographic desensitizer.

Example 47.----[2-(1-ethylquinoline) [2-(3-ethylbenzthiazole)]-Y-anilomethyltrimethincyanine iodide 3ethyl-2-dianiloisopropylidenebenzthiazoline (0.77 g.; 1 mol.) and aquinaldine (0.6 g.; 1 mol.) were ground together and pyridinc (4 cc.)was added. The mixture was heated for 10 minutes in a glycerine bath at60-69" C. The reaction mixture was cooled and the product precipitatedwith absolute ether. It was filtered off and washed with ether. It wasground with water, filtered and dried. It was then extracted with etherin a Soxhlet apparatus. The residue was recrystallized from methylalcohol. The dark maroon crystals had M. P. about 210 C. (decomp.). Abs.max. of ammoniacal methyl alcoholic solution at 5150 A, while a sulfuricacid methyl alcoholic solution had its maximum at 4750 A. sensitized aphotographic gelatinosilver-bromide emulsion weakly, with the maximum6000 A. and strong blue depression. This preparation can be effected inboiling absolute alcohol for 1 minute, instead of in warm pyridine for10 minutes.

Example 48.Bis 2 (3-ethylbenethiazole)-aanilomethyltrimethincyanineiodide 3 ethyl-2-dianiloisopropylidenebenzthiazoline (0.19 g.; 1 mol.)and 2-methylbenzthiazole ethiodide (0.15 g.; 1 mol.) were groundtogether and pyridine (1 cc.) was added. Reaction occurred even in thecold, as indicated by development of a red color. The mixture was heatedfor 5 minutes in a glycerine bath at 60-87 C. It was cooled and theproduct was precipitated by adding ether. The precipitated product wasground with water, dried and extracted with ether in a Soxhletapparatus. The extracted dye was recrystallized from methyl alcohol. Thedark maroon powder had an indefinite M. P. at about 210 C., with decomp,from 180 C. A methyl alcoholic solution containing pyridine had its abs.max. at 5515 1 1., and one containing sulfuric acid its max. at 4695.There was no photographic sensitization but depression of the normalblue sensitivity.

Example 49.-[2 (B-ethyZ-M-thiazoline) [2-(3- ethylbenzthiazolefl7-anil0methyltrimethincyanine iodide 3ethyl-2-dianilois0propylidenebenzthiazoline (0.77 g.) andZ-methyl-M-thiazoline ethiodide (0.62 g.) were stirred together inice-cold pyridine (4 cc.). After six hours in ice, the red solution wastreated with ice-cold water. The resultant red oil solidified and waswashed, then recrystallized from absolute alcohol. The bright redcrystals began to shrink at about C. and to darken at about C.;considerable decomposition occurred from -130" C. but there was nodefinite M. P. A methyl alcoholic solution containing pyridine had abs.max. at 4005 and 4905 A. One containing sulfuric acid had the max. at4235. The dye weakly sensitized a gelatino-silver-chloride emulsion to5000 1 1., with max. at 4500.

Example 50.-*[4 1 ethylquinoliize) 1 r2 4 methyl 3 ethylihiazole)l-y-anilo'methyltrimethincyanine iodide 4methyl-3-ethyl-2-dianiloisopropylidene-M- thiazoline (1.16 g.) lepidineethiodide 1.0 g.) and pyridine (15 cc.) were heated together at 100 C.for 4 minutes. The dye was precipitated with ether, washed with water,and recrystallized from methyl alcohol. The dark green crystals had M.P. 211 C. (decomp). An ammoniacal methyl alcoholic solution had its abs.max. at 5720 A. and one containing sulfuric acid has its max. at 5010 A.The dye sensitized weakly a gelatino-silverbromide emulsion to 5500 A.with slight depression of the normal sensitivity.

Example 51.[2 (1 ethylquinolinellEZ-(4- methyl 3 ethylthiazole)l-Y-aniZOmethyZtTimethincyanine iodide This preparation was similar tothat of Example 50, except that quinaldine etho-p-toluenesulfonate wasused instead of lepidine ethiodide. The crude dye was precipitated withether and the sticky solid was dissolved in hot spirit and convertedinto dye iodide by treatment with aqueous potassium iodide solution. Thedye was twice'recrystallized from methyl alcohol. The purple crystalshad M. P. 217 C. (decomp.), An ammoniacal methyl alcoholic solution hadabs. max.' at 5060 A. and one containing sulfuric acid had max. at 4815A. On a gelatino-silver-chloride emulsion, it conferred sensitivity asfar as 5900 with the maximum at 5250 A.

Example 52.--[2-(S-ethgjl-M-thiazolineh] [2- (4- methyl 3ethylthiazole)l-y-anilomethyltrimethincyanine iodide Example53.[4-(I-eihylquinoline) [2- (3-eth'yl- A -thiazoline)] 7anilomethyltrimethincyanine iodide 3 ethyl 2dianiloisopropylidenethiazolidine (4.48 g.) lepidine ethiodide (4.4 g.)and absolute ethyl alcohol (160 cc.) were mixed at C. and kept at thistemperature for an hour. The washed product was recrystallized frommethyl alcohol. Its dark green crystals had M. P. 133 C. (decomp.). Amethyl alcoholic solution containing pyridine had its abs. max. at 5810A. and one containing sulfuric acid had the max. at 4950 A.

Example 54.-[2-(3-ethyl-A -thiazoline) l [2-(3- ethylbenzthiaeole) l-aanilomethyltrimethincyanine iodide.

This was prepared as in Example 53, with 2- methylbenzthiazole ethiodidetaking the place of the lepidine ethiodide. The brick red crystals hadM. P. 110 C. (decomp.). A methyl alcoholic solution containing pyridinehad its abs. max. at 5100 A. whilst that of one containing sulfuric acidwas at 4725 A.

Example 55.[Bis 2-(3-ethyl-A -thiazoline) 1aam'lomethyltrimethincyanineperchlorate This was prepared, similarly to Example 53, from 3methyl-2-dianiloisopropylidenethiazolidine and 2-methyl-A -thiazolinemethiodide, in ice-cold pyridine. The dye iodide was precipitated withice-cold water. washed with ether, taken up in not absolute alcohol andconverted into perchlorate by treatment with a hot aqueous solution ofsodium perchlorate. This was recrystallized from methyl alcohol andobtained as orange crystals, M. P. 148 C. (decomp.), with previousdarkening anad shrinking. Abs. max. of a methyl alcoholic solutioncontaining pyridine was at 4500 A. and one containing sulfuric acid hadits abs. max. at 4370 A.

Example 56.-[Bis2-(3-ethylben2thiazole) [we'- dimethin-2'-(3'-ethylbeneselenazole) Jtrimethincyanine diiodide[Bis-2-(3-ethylbenzthiazole) 1a anilomethyltrimethincyanine iodide (0.30g.; 1 mol.) Z-methylbenzselenazole ethiodide (0.18 g.; 1 mol.) andanhydrous sodium acetate (0.13 g.; 4 mols.) were ground together withacetic anhydride (2 cc.) and heated at -150 C. for 5 minutes. The dyeseparated from the reaction mixture.

It was filtered 01f, washed with ether and then with a little water andwas recrystallized from methyl alcohol. When heated, the dark greencrystals of dye decomposed at about 234 C., but depending upon the rateof heating. Abs. max. of methyl alcoholic solution at 6100 A. Itstrongly desensitized photographically and did not sensitize.

Example 57.[2- (I-ethylquinoline) [2-(3-ethylbenzthiazole) ['yfidimethin-W- 3 '-ethylbenzthiazole) ltrimethincyanine diiodide[2-(l-ethylquinoline)l[2 (3 ethylbenzthiazole) 1vanilomethyltrimethincyanine iodide (1.18 g.), 2-methylbenzthiazoleethiodide (0.61 g.), anhydrous sodium acetate (0.65 g.) and aceticanhydrlde (8 cc.) were heated together at 140-150 C. for 2 minutes. Thesolid was filtered off when cold, washed with ether, ground with water,and recrystallized from methyl alcohol. The bronze crystals had M. P.228 C. (decomp.). Abs. max. of methyl alcoholic solution at 6110 A. Thedye desensitized a gelatinosilver-bromide photographic emulsion and didnot sensitize.

Example 58.---[4-(I-ethylquinoline) [2-(3-ethylbenzthiazoleflhfi'dimethin-Z' (3' ethylbenzthiazole) ltrimethincyanine diiodide [4-(1ethylquinoline)][2-(3 ethylbenzthiazole) ]'y anilomethyltrimethincyanineiodide (1.18 g.), 2-methylbenzthiazo1e ethiodide (1.84 g.), anhydroussodium acetate (1.0 g.) and acetic anhydride (15 cc.) were heatedtogether at 140- C. for 8 minutes. The reaction mixture was worked up asin Example 57 and the dye fractionally recrystallized frommethylalcohol. The bronze powder had M. P. 210-212 C. (decomp.). withprevious softening. Abs. max. of methyl alcoholic solution at 6480A.

Example 59.[Bis-2 (3-ethyl-A thiazoline) [ozfl' dimethin 2' (3'ethylbenzthiazole) trimethincyanine diperchlorate [2-(3-ethyl A2thiazoline)][2-(3-ethylbenzthiazole) la-anilomethyltrimethincyanineiodide (1.82 g.), 2-methyl-A -thiazoline ethiodide (1.71 g.), andpyridine (15 cc.) were heated together at 120 C. for 3 minutes. Absoluteether precipitated a sticky solid. which was dissolved in hot spirit andtreated with a hot aqueous solu- StAKUH HUUi 25 tion of sodiumperchlorate (1.9 g. The washed dye was recrystallized from methylalcohol, being freed from a residue. The green crystals had a goldreflex. M. P. 235 C. (decomp.). Abs. max. at 5580 A. for the methylalcoholic solution. Example 60.[2-(l-ethylquinoline) [2-(3-ethlbenzthzazole) [7;9'-dimethin-4- (1 'ethylquinoline)] trimethzncyaninedz'iodide CH=CH B [4-(1-ethylquinoline)] [2-(3 ethylbenzthiazole)l7-anilomethyltrimethincyanine iodide (1.18 g.), quinaldine ethiodide(0.60 g.), anhydrous sodium acetate (0.66 g.) and acetic anhydride cc.)were heated together at 140-150 C. for minutes. The reaction mixture wastreated with anhydrous ether and the resultant solid well washed withwater and recrystallized from methyl alcohol. The brownish bronzecrystalline powder had M. P. 253 C. (decomp.). Its methyl alcoholicsolution had its abs. max. at 6730 A. The dye caused weak sensitizationand strong desensitization of a gelatino-silver-bromide photographicemulsion.

Example 61.The dye of Example 60 was also prepared by heating together[2-(1-ethylquinoline) [2-(3-ethylbenzthiazoie) ['yanilomethyltrimethincyanine iodide, lepidine ethiodide, sodium acetate,and acetic anhydride. The crude product was isolated and purified asbefore. Example 62.[2- (I-ethylquinoline) [2-( 3-eth1/lbenzthiazoleH[vW-dimethin 2' (3' ethylbenzselenazole) ltrimethincyanine cliz'odide[2-(1-ethylquinoline)l [2 (3 ethylbenzthiazole)lY-anilomethyltrimethincyanine iodide (0.29 g.; 1 mol.),2-methylbenzthiazole ethiodide (0.18 g.; 1 mol.) and anhydrous sodiumacetate (0.16 g.; 4 mols.) were ground together with acetic anhydride (2cc.) and heated at 140150 C. for 2 minutes. The original bluish purplecolor changed to blue and dye crystallized even from the hot reactionmixture. After cooling, the dark green solid was filtered oil andwashed, first with ether and then with a little water. The dye wasrecrystallized from methyl alcohol and gave a blue spirit solution.

Example 63.[4- (1 -ethylquz'nolz'ne) l [2- (Ii-ethyl- A -thiazolinen wedimethin 2'-(3'-ethylbenzthiazole) ltrimethincyanine diiodide[4-(1-ethylquinoline)li2-(3 ethyl-A -thiazoline)] Yanilomethyltrimethincyanine iodide (1.35 g.), 2-methylbenzthiazoleethiodide (0.84

g. and pyridine cc.) were boiled together for 2 minutes. The washedsolid was recrystallized from methyl alcohol and obtained as goldcrystals, M.P. 242 C. (decomp.). Abs. max. of

methyl alcoholic solution at 6555 A.

Example 64.[2- (3-ethyl-A -thz'azolz'ne) [2-(4- methyl-.l-ethylthiazole)['yB'-dimethin-2'-(3'- ethyl A -thiazoline) ltrimethzncyam'nediperchlorate [2-(3-ethyl-A thiazoline)l [2-(4-methyl-3- ethylthiazole)]Y anilomethyltrimethincyanine iodide (1.28 g.), 2-methyl-A -thiazolineethiodide (0.99 g.) anhydrous sodium acetate (0.82 g.) and aceticanhydride (20 cc.) were heated together at -150 C. for 5 minutes.Precipitation with absolute ether was carried out and the product washedwith water. The sticky residue was dissolved in hot spirit and treatedwith a hot aqueous sodium perchlorate solution. The dye perchlorate wasrecrystallized from methyl alcohol and obtained as maroon crystals, M.P. 220 C. (decomp.). Abs. max 5050 A. for a methyl alcoholic solution.It sensitized a gelatino-silverbromide photographic emulsion to 5800 A.with the maximum at 5300.

Example 65.--[5- (3-ethylrhodanine) [2- (Ii-ethylbenzthiazole) 1panilomethz ldimethlnmerocyanine 3-ethyl-2dianiloisopropylidenebenzthiazoline (0.77 g.; 1 mol.) and3-ethylrhodanine (0.97 g.; 3 mols.) were mixed and pyridine (4 cc.)added. The mixture was heated in a glycerine bath at 60-65 C. for 1minute. The mixture was cooled and absolute ether (20 cc.) added. Thered solid was filtered off, washed with absolute ether andrecrystallized from pyridine, a second crop of crystals being obtainedupon the addition of ether to the pyridine mother liquor. When heatedthe red crystals began to blacken at about C., were quite black andshrunken at C., and melting at about C. (decomp.). An ammoniacal methylalcoholic solution had its absorption maximum at 5230 A. while onecontaining sulfuric acid had the maximum at 4400 A. The dye sensitized agelatino-silver-bromide emulsion to 6420 A., the maximum lying at 5700.

Example 66.[5-(4-lceto-2-thio-3-ethyltetrahydro omazole) [2 (3ethylbenzthiazole) 1c anz'lomethyldimethinmerocyanine 3-ethyl2-dianiloisopropylidenebenzthiazoline (3.83 g.),4-keto-2-thio-3-ethyltetrahydro-oxazole (2.90 g.) and pyridine (20 cc.)were heated together at 50-63 C. for 30 minutes. The cooled reactionmixture. from which dye crystallized, was treated with absolute ether.The dye was filtered off, washed with ether, and purified by boiling outwith methyl alcohol. The red residue began to darken at about 195 C. andmelted at about 208 C. (decomp.). Abs. max. of ammoniacal methylalcoholic solution at 4975 A, while methyl alcoholic solution containingsulfuric acid had abs. max. at 4100 A. It sensitized agelatinosilver-chloride emulsion to 5400 A. with the maximum at 4800.

Example 67. [5-(1-phenyl-3-ethyl-Z-thio-hydantoin)[2-(5-chloro-3-ethylbenzthiazole) ,3-anilomethyldimethinmerocyanine5-chloro-3-ethyl-2-dianiloisopropylidenebenz thiazoline (1.56 g.),1-phenyl-3-ethyl-2-thiohydantoin (2.48 g.) and pyridine (15 cc.) wereheated together at 130-135 C. for 5 minutes. The product wasprecipitated by water, and boiled out twice with methyl alcohol. Theresidue was taken up'in hot acetic acid and the cooled filtrateprecipitated with ether. The brick red powder had M. P. 242-243 C.(decomp). with shrinking from 137 C. A methyl alcoholic solutioncontaining ammonia had its abs. max. at 5110A. and one containingsulfuric acid-had its abs. max. at 4300. The dye sensitized agelatinosilver-chloride emulsion to 6000 A. with the maximum at 5500.

Example 68. [-(2-diphenylamino-4-keto-A thz'azolinellm (5-chloro 3ethylbenzthi azole) lB-anilomethyldimethinmerocyanine 5-chl0ro-3-ethyl-2dianiloisopropylidenebenzthiazoline (1.04 g), 2-diphenylamino-4-keto-Athiazoline (2.02 g.) and pyridine cc.) were heated together in a steambath for 1 minute. The dye was precipitated with ether andrecrystallized twice from methyl alcohol. The bright yellow powder hadM. P. 245 C. (decomp). An ammoniacal methyl alcoholic solution had itsabs. max. at 4835 A. One containing sulfuric acid had its abs. max. at4250 A. It sensitized a chloro-silver-bromide emulsion to 5900 A. withthe maximum at 5200.

Example 69. [5-(3 ethylrhodaninel l [2-(3 ethylbeneselenaeole) loanilomethyldimethinmerocyanine 3-ethyl-2dianiloisopropylidenebenzselenazo line (0.86 g.), 3-ethylrhodanine (0.96g.) and pyridine (5 cc.) were heated together at 120 C. for 3 minutes.The product, precipitated by means of absolute ether, was recrystallizedfrom a mixture of pyridine and methyl alcohol (1:1). The lustrousVermilion crystals had M. P. 197 C. (decomp). An ammoniacal methylalcoholic solution had abs. max. at 5100 A. One containing sulfuric acidhad its abs. max. at 4400. The dye sensitized a washedgelatino-silver-chloride emulsion, the maximum lying at 5700 A. andsensitization extending to 6300.

Example 70.[5-(4-keto-2-thio 3 ethyltetrahydro occaeole) [2(3-ethyZbenzselenazoleH B-anilomethyldimethinmerocyanine In place of the3-ethylrhodanine in Example 69, there was used4-keto-2-thio-3-ethyltetrahydro-oxazole. The dye was isolated as inExample 69. It was recrystallized from a mixture of pyridine and ethylalcohol (1:1). The bright orange crystals had M. P. 161 C. (decomp). Anammon acal methyl alcoholic solution had its abs. max. at 4850 A. andone containing sulfuric acid had its abs. max. at 4105. The dyesensitized a gelatino-silver-chlorobromide emulsion to 5900 A. with themaximum at 5400.

Examp e 71.[5-(12Jhenyl-3-ethyl 2 thiohydantoin)[2-(3-ethylbenzselenaeole) l6 anilomethyldimethinmerocyanine In place ofthe ethylrhodanine in Example 69, there was used1-phenyl-3-ethyl-2-thiohydantoin. The red reaction mixture was pouredinto water. The aqueous liquid was decanted off and the sticky residueboiled out with methyl alcohol. The residual dye was recrystallized frompyridine. The brick red crystals had a gold re flex. M. P. 236 C.(decomp). An ammoniacal methyl alcoholic solution had its abs. max. at5055 A. and one containing sulfuric acid had the max. at 4290 A. The dyesensitized a gelatinosilver-chloride emulsion to 6150 A. with the max.at 5600.

Example 72.[2-(4-methyl- 3 -ethylthiazole) l [5- (3-ethylrhodanz'ne)czanilomethyldimethinmerocyamne 4-methyl- 3-ethyl-Z-dianiloisopropylidene-A thiazollne (0.69 g.), 3-ethylrhodanine(0.48 g.), and absolute ethyl alcohol ('7 cc.) were boiled and stirredtogether for 2 minutes. The resultant dye was filtered oiT when cold andwas recrystallized from a mixture of pyridine and absolute ethyl alcohol(2:5). The crimson crystals had M. P. 182 C. (decomp). An ammoniacalmethyl alcoholic solution had its abs. max. at 4085 A. and a secondarycrest at 4830. One containing sulfuric acid had its abs. max. at 4465 A.The dye sensitized a gelatino-silver-chloride emulsion to 6400 A. withthe maximum at 5850.

Example 73 -[5-(4-keto-2-thio- 3 -ethyltetrahy dro-oxazole) l [2-(4-methyl- 3 ethylthz'azole) l- 9-anilomethyldimethinmerocyanine4-methyl-3-ethyl- 2 -dianiloisopropylidene- A thiazoline (1.74 g.),4-keto-2-thio-3-ethyltetrahydro-oxazole (1.6 g.) and pyridine (10 cc.)were heated together at C. for 10 minutes. The reaction mixture waspoured into water. The acqueous layer was decanted ofi and the stickysolid boiled out with absolute ethyl alcohol. The residue wasrecrystallized from methyl alcohol. The bright orange crystals had M. P.C. (decomp.). An ammoniacal methyl alcoholic solution had its abs. max.at 4510 A. One containing sulfuric acid had its abs. max. at 4150. Thedye sensitized a gelatino-silver-chloride emulsion to 5700 A., themaximum lying at 5200.

Example 74.[5-(1-phenyl- 3 -ethyl- 2 -thz'ohydantoin) [2-( 4 methyl- 3-ethylthiaz0le) l5- anilomethyldimethinmerocyanine 4-methyl-3-ethyl- 2-dianiloisopropylidene-A thiazoline (3.47 g.),l-phenyl-3-ethyl-2-thiohydantoin (3.3 g.), and absolute ethyl alcohol(20 cc.) were boiled together for 3 minutes. The solid was filtered 01fand purified by boiling out twice with methyl alcohol.

Example 75.-The dye of Example '74 was prepared by heating the reactantsfor 4 minutes in pyridine at 130 0., instead of using ethyl alcohol. Thesolution was poured into water and the crude product thus obtained waspurified by boiling out with methyl alcohol and then recrystallized frompyridine. The maroon and gold crystals had M. P. 222 C. (decomp.). Anammoniacal methyl alcoholic solution had its abs. max. at 4860 A. andone containing sulfuric acid had the max. at 4470 A. The dye sensitizeda gelatino-silverchloride emulsion up to 5200 A. with the maximum at4850.

O N-CzHt [5-(3 ethy1rhodanine)][2 (S-ethylbenzthiazole)3-anilomethyldimethinmerocyanine (0.45 g.; 1 mol.), 4-keto-2-thio- 3-ethyltetrahydro-oxazole (0.29 g.; 2 mols.) anhydrous sodium acetate(0.33 g.; 4 mols.) and acetic anhydride (.0 cc.) were stirred togethermechanically in an oil bath at 140-.150 C. for 5 minutes. The reactionmxture was cooled and absolute ether (30 cc.) added. The solid wasfiltered oiT. washed with ether, ground with water and dried. The darkred solid gave a red spirit solution.

Example 77.--Th dye of Example '76 was also prepared from[5-(4-keto-2thio-3-ethyltetrahydro-oxazole) [2- (3 -ethylbenzthiazole)l-fi-anilomethyldimethinmerocyanine, 3-ethylrhodanine, and sodiumacetate in acetic anhydride. It was purified by dissolving in hotpyridine, cooling and precipitating with ether. The maroon solid had nodefinite M. P. but decomposition and melting took place from 215-270 0.Abs. max. of methyl alcoholic solution at 5475 A. The dye decreased theblue sensitivity of a gelatinosilver-bromide emulsion and sensitizedweakly from 5600 to 6000 21.

Example 78.[-(4-keio-2-thio- 3 -ethyltetrahydro-orazole) ][2- (4-methyl-3 -ethylthiazole) iB-methin 5'-(3'-ethylrhodanine) ldz'methinmerocyanine[2-(4methyl-3-ethylthiazole) [5- (3-ethylrhod a n in e) laanilomethyldimethinmerocyanine (1.04 g.), 4-keto-2-thio- 3-ethyltetrahydro-oxazole (0.73 g.), anhydrous sodium acetate (0.82 g.)and acetic anhydride cc.) were heated together at 145-150 C. for '7minutes. The reaction mixture was poured into water. The aqueous liquidwas decanted off and the residu induced to crystallize by stirring inspirit. It was recrystallized from methyl alcohol. The purple crystalshad M. P. 215 C. (decomp). A methyl alcoholic solution had abs. max. at5545 A. The dye sensitized a gelatino-silver-bromide emulsion weakly to6000 A. with the maximum at 5500, and strong depression of the normalblue sensitivity. To a gelatino-silver-chloride emulsion it was a strongsensitizer, the action extending to 6500 A.

Example 79.[5-(4-keto-2-thio-3-ethyltetrahydro oxazole) [2(S-ethylbenzselenazole) 9- methzn-5'- (3'-ethylrhodanine)ldimethinmerocyanine.

This was carried out as in Example 78, except that the first reactantthere mentioned was replaced by [5- (3-ethylrhodanine) l- [2-(3-ethylbenzselenazole) 1B anilomethyldimethinmerocyanine, and the dyewas similarly purified. Its dark purple crystals had M. P. 135 C.(decomp.) Abs. max. at 5190 A. in methyl alcoholic solution. The dyedecreased the blue sensitivity of a gelatino-silver-bromide emulsion,while introducing weak sensitivity up to 6100 A.

Example 80.[5-(3-ethylrhodanine) [2-(3-ethylbenzthiazole) [[i-methin-F-(3- ethylrhodanine) JdimethinmerocZ/anine This dye which is alsodescribed in Example 3'7 can also be prepared as in Example '78, i. e.as follows: [5- (3-ethylrhodanine) [2- (3-ethylbenzthiazole) canilomethyldimethinmerocyanine (0.45 g.; 1 mol.), 3-ethylrhodanine (0.32g.; 2 mols.), anhydrous sodium acetate (0.33 g.; 4 mols.) and aceticanhydride (10 cc.) were stirred together mechanically in an oil bath at140-150 C. for 5 minutes. The reaction mixture was cooled and treatedwith absolute ether 00.), the solid was filtered off, washed with ether,

30 ground with water, and dried. It was beautifull crystalline and gavea bluish pink spirit solution.

Example 81 .[5- (3-ethylrhodanine) [2- (3-ethylbenzthiazole) [513'dimethin 2' -(1-ethylquinolinium iodide) ldimethinmerocyanine [5 (3ethylrhodanine)][2 (3 ethylbenzthiaz0le)] panilomethvldimethinmerocyanine (0.45 g.; 1 mol.), quinaldine ethiodide(0.30 g.; 1 mol.) anhydrous sodium acetate (0.33 g.; 4 mols.) and aceticanhydride (10 cc.) were stirred together mechanically in an oil bath at-150 C. for 5 minutes. The reaction mixture was cooled and absoluteether (30 cc.) added; the solid was filtered off, washed with ether,ground with water, and dried. The dark green crystals of dye gave a bluespirit solution.

Example 82.--[5 -(3-ethylrhodanine) 1 [2-(3-ethylbenzselenaziole)Emadimethin-2'-(3'-ethylbenzthiazolium iodide) ldz'methinmerocyanineExample 83.[5- (3-ethylrhodan2'ne) [2-(3-ethylbeneselenazole)[cfifdimethin-2'- (3'-ethylbenzselenazolium iodide)ldz'methinmerocyanine This was made as in Example 81 except that2-methylbenzselenazole ethiodide took the place of Z-methylbenzthiazoleethiodide used there. After recrystallization from methyl alcohol thedark purple crystals had M. P. 245 C. (decomp.) Abs. max. at 5820 A. fora methyl alcoholic solution. There was no sensitization but strongdesensitization of a photographic silver halide emulsion.

Ezample 84.[5-(3-ethylrhodanine) [2-(t =ethylbenaselenazole) [fiB'-dimethin-2'- (3'-ethyl- 6':7' benzbenzthiazolium iodide)ldim'ethinmerocyanine This was made as in Example 81, except that the2-methylbenzthiazole ethiodide was replaced by2-methyl-6:7-benzbenzthiazole ethiodide. The dye was boiled out with andrecrystallized from methyl alcohol. The blue green crystals had M. P.240 C. (decomp.). Abs. max. at 5930 A. for a methyl alcoholic solution.The dye depressed the blue sensitivity of a gelatino-silverbromideemulsion and did not confer extrasensitivity.

Example 8 5.-[2 (.4 methyl 3-ethylthiazole)] [-(3- ethylrhodanine)[CCfidimethin-2-(3'- ethyl 6'27 benzbenzthiazolium iodide)1dimethinmerocyamne [2-'(4-methyl-S-ethylthiazole) [5-(3-ethylrhodanine)a anilomethyldimethinmerocyanine (0.83 g.),Z-methyl-Gz7-benzbenzthiazole ethiodicle (1.42 g.), anhydrous sodiumacetate (0.66 g), and acetic anhydride (30 cc.) were heated together at145-150 C. for 3 minutes. The dye was precipitated with ether andtreated with hot waer. The undissolved residue was recrystallized frommethyl alcohol. The brilliant green crystals had M. P. 260 0. (decomp.).Abs. max. at 5945 A. in methyl alcoholic solution. The dye decreased theblue sensitivity of a gelatino-silver-bromide emulsion and did notconfer extra-sensitivity.

Example 86.[2- (4-methyl-3-ethylthiazole) l [5- (3 ethylrhodanine) [ae'dimethin 2' (3- ethylbenzthiazolium iodide) ldimethinmerocyanine Thiswas prepared as in Example 85, but the part of2-methyl-6:7-benzbenzthiazole ethiodide.

was played by Z-methylbenzthiazole ethiodide. After boiling out withmethyl alcohol, the dye was recrystallized from acetic acid. The emeraldgreen crystals had M. P. 240 C. (decomp). Abs.

max. at 5750 A. The dye did not sensitize a gelatino-silver-bromideemulsion and depressed the blue sensitivity.

Example 87.[5- (1-phenyZ-3-ethyZ-2-thi hydantoz'n) [2-( 4methyZ-S-ethylthiazole) [pH-dimethz'n-Z (3 ethylbenzthiazolium iodideHdimethz'nmeroc'yanine [5-(1-phenyl-3-ethyl-2-thiohydant0in) [2-(4-methyl 3 ethylthiazo1e)l B anilomethyldimethinmerocyanine (1.19 g.)2-methyl-benzthiazole ethiodide (1.53 g.) anhydrous sOdium acetate (0.82g.), and acetic anhydride (30 cc.) were heated together at 145-150 C.for 5 minutes. The product was precipitated with ether, washed with warmwater, and boiled out with methyl alcohol. Recrystallization of theresidue from methyl alcohol gave dark green crystals, M. P. 225 C.(decomp). Abs. max. at 5765 A. for a methyl alcoholic solution. The dyedecreased the sensitivity of a photographic silver halide emulsion.

Example 88. [2 (4 methyZ-S-ethylthiazole) l [5 lS-ethylrhodanine) l[aB'-dz'methin-2-(3' ethyl s -thiazolium iodide) ldzmcthinmerocyamine [2(3-ethyll -thiazoline) l [2 (4 methyl-3- ethylthiazole)lanilomethyltrimethincyanine iodide (1.02 g.) 3-ethylrhodanine (0.48 g.)anhydrous sodium acetate (0.66 g.), and acetic anhydride (15 cc.) wereheated together at 140-150 C. for 5 minutes. The dye was precipitatedwith ether and ground with water, then recrystallized from methylalcohol. The purple crystals had M. P. 214 C. (dccomp). Abs. max. at5360 A. for a methyl alcoholic solution. It sensitized agelatino-silver-bromide emulsion up to 6200 A., with the maximum at 5900A, considerably decreasin": the blue sensitivity.

In connection with the above-described condensations involving compoundscontaining a reactive methylene group adjacent to a carbonyl 32 group,non-cyclic as well as cyclic compounds can be employed. Examples ofcompounds in which the reactive methylene group is in an open chain aremalonic acid, malonic esters, malononitrile, malonamide, alkyl2-quinolylpyruvates, acetylacetone, acetoacetamides, cyanoacetanilide,benzoylacetonitrile, hippuric acid, aceturic acid andp-nitrobenzylcyanide.

The polymethin dyes set forth by formulas II, III, IV, V, VIII, IX and Xcan be incorporated in photographic silver halide emulsions and some ofthem act to spectrally (optically) sensitize the emulsions. The effectof several of such dyes on photographic silver halide emulsions is shownin the foregoing examples. All of such dyes can be employed aslight-screening substances in the preparation of photographic materials.

The aforesaid dyes are useful for extending the spectral sensitivity ofthe customarily employed gelatino-silver-chloride,gelatino-silverchlorobromide, gelatino-silver-bromide,gelatinosilver-chloroiodide, gelatino-silver-chlorobromiodide, andgelatino-silver-bromiodide developingout emulsions. To prepare emulsionssensitized with one or more of our new dyes, it is only necessary todisperse the dye or dyes in the emulsions. The methods of incorporatingdyes in emulsions are simple and are well known to those skilled in theart. In practice it is convenient to add the dyes to the emulsions inthe form of a solution in an appropriate solvent. Methanol has provensatisfactory as a solvent for most of our new dyes. With some of thedyes acetone or ethyl alcohol can be used. The dyes are advantageouslyincorporated in the finished, washed emulsions and should be uniformlydistributed throughout the emulsion.

The concentration of the dyes in the emulsions can vary widely, e. g.from 5 to mg. per liter of flowable emulsion. The concentration of thedyes will vary according to the type of emulsion and according to theeffects desired. The suitable and most economical concentration for anygiven emulsion will be apparent to those skilled in the art, upon makingthe ordinary tests and observations customarily employed in the art ofemulsion making. To prepare a gelatino-silver-halide emulsion sensitizedwith one or more of our dyes, the following procedure is satisfactory: Aquantity of dye is dissolved in methyl alcohol or other suitable solventand a volume of this solution (diluted with water, if desired)containing from 5 to 100 mg. of dye, is slowly added to about 1000 cc.of gelatino-silver-halide emulsion, with stirring. Stirring is continueduntil the dye is thoroughly dispersed in the emulsion. With most of ourdyes, from 10 to 20 mg. of dye per liter of emulsion suffices to producethe maximum sensitizing effect. With the finer grain emulsions somewhatlarger amounts of dye may be needed to produce the maximum effect.

The above statements are only illustrative, as it is apparent that thedyes'can be incorp zrated in photographic emulsions by any of the othermethods customarily employed in the art, e. g. by bathing a plate orfilm upon which an emulsion is coated in a solution of the dye in anappropriate solvent. However, bathing methods are ordinarily not to bepreferred. Emulsions sensitized with the dyes can be coated on suitablesupports, such as glass. cellulose derivative film, resin film or paperin the usual manner.

What we claim as our invention and desire to be secured by LettersPatent of the United States is:

DEREK/fl ilUUl 1. The dianiloisopropylidene compounds which arerepresented by the following general formula:

CH=N-Ar1 wherein R2 represents an alkyyl group, n represents a positiveinteger of from 1 to 2, Z represents the non-metallic atoms necessary tocomplete a heterocyclic nucleus containing from 5 to 6 atoms in theheterocyclic ring, and Ari and Ar: each represents an aryl group.

2. The dianiloisopropylidene compounds which are represented by thefollowing general formula:

GE -NAT CH=NAr2 wherein R2 represents a primary alkyl group of theformula CmH2m+1 wherein m represents a positive integer of from 1 to 4,Z represents the non-metallic atoms necessary to complete a heterocyclicnucleus of the benzthiazole series, and An and Arz each represents anaryl group of the benzene series.

3. The dianiloisopropylidene compound which is represented by thefollowing formula;

4. The dianiloisopropylidene compound which is represented by thefollowing general formula:

CH=NA I:

wherein R2 represents a primary alkyl group of the formula CmH2m+lwherein m represents a positive integer of from 1 to 4, Z represents thenon-metallic atoms necessary to complete a heterocyclic nucleus of thebenzselenazole series, and An and AM each represents an aryl group ofthe benzene series.

5. The dianiloisopropylidene compound which is represented by thefollowing formula:

6. The dianiloisopropylidene compounds which are represented by thefollowing general formula:

wherein R2 represents an alkyl group of the formula CmH2m+1 wherein mrepresents a positive integer of from 1 to 4, Z represents thenonmetallic atoms necessary to complete a heterocyclic nucleus of thethiazole series and An and Arz each represents an aryl group of thebenzene series.

7. The dianiloisopropylidene compound which is represented by thefollowing formula:

CgH5

8. A process for preparing a dianiloisopropylidene compound comprisingcondensing, in the presence of a water-binding agent, analkylisoformanilide selected from those represented by the followinggeneral formula:

wherein R1 represents an alkyl group and AI'l represents an aryl groupof the benzene series with a heterocyclic nitrogen base selected fromthe heterocyclic nitrogen bases represented by th following generalformula:

a iii-N10 H=C H) "S c: CH2 wherein R2 represents an alkyl group, nrepresents a positive integer of from 1 to 2, and Z represents thenon-metallic atoms necessary to complete a heterocyclic nucleuscontaining from 5 to 6 atoms in the heterocyclic ring.

9. A process for preparing a dianiloisopropylidene compound comprisingcondensing, in the presence of zinc chloride, an alkylisoformanilideselected from those represented by the following general formula:

wherein R1 represents an alkyl group and Ari represents an aryl group ofthe benzene series with a heterocyclic nitrogen base selected from theheterocyclic nitrogen bases represented by the following generalformula:

wherein R2 represents an alkyl group, n represents a positive integer offrom 1 to 2, and Z represents the non-metallic atoms necessary tocomplete a heterocyclic nucleus containing from 5 to 6 atoms in theheterocyclic ring.

10. A process for preparing a dianiloisopropylidene compound comprisingcondensing, in the presence of zinc chloride, an alkylisoformanilideselected from those represented by the following genera1 formula:

wherein R1 represents a primary alkyl group of the formula CmH2m+1wherein 112 represents a positive integer of from 1 to 4, and Arirepresents an aryl group of the benzene series, with a heterocyclicnitrogen base selected from those which are represented by the followinggeneral formula:

I R2-N--b=om wherein R2 represents a primary alkyl group of the formulaCmH2m+1 wherein m represents a positive integer of from 1 to 4, and Zrepresents the non-metallic atoms necessary to complete a heterocyclicnucleus of the benzthiazole series.

11. A process for preparing a dianiloisopropylidene compound comprisingcondensing, in the presence of zinc chloride, an alkylisoformanilide 35selected from those represented by the following general formula:

wherein R2 represents a primary alkyl group of the formula CmH2m+1wherein m represents a positive integer of from 1 to 4, and Z representsthe non-metallic atoms necessary to complete a heterocyclic nucleus ofthe benzoselenazole series.

12. A process for preparing a dianiloisopropylidene compound comprisingcondensing, in the presence of zinc chloride, an alkylisoformanilideselected from those represented by the following general formula:

wherein R1 represents a. primary alkyl group of the formula CmH2m+1wherein m represents a positive integer of from 1 to 4, and Anrepresents an aryl group of the benzene series, with a heterocyclicnitrogen base selected from those which are represented by the followinggeneral formula:

wherein R2 represents a primary alkyl group of the formula CmH2m+1wherein m represents a positive integer of from 1 to 4.

FRANCES M. HAMER. RUSSELL J. RATHBONE. BARBARA SEATON WINTON.

No references cited.

Certificate of Correction Patent No. 2,484,503 October 11, 1949 "FRANCESM. HAMER ET AL.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows:

Column 22, line 28, after benzbenzthiazoline, and before etc. inserts-etciltyzl-2-methylene-6fl-benzbenzthiazolme,; column 9, line 47, inthe formula, for Z rea column 19, line 18, fordianiloisopropylidenebenzthiazoline" read dia'mllo'iso-{JigpyZ'idenebenzselenazoline; column 33, line 8, for alkyyl read alkyl;column 34,

e 45, strike outR O-CH=NA1' column 35, lines 8 and 9, forheteracyclicread heterocycl'ic; a I

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 7th day of March, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommzssz'oner of Patents.

